Introduction
It’s time for another blast from the past review – this time covering the Sigma 105mm f/1.4 DG HSM ART in Nikon F mount. Good ol’ Markus in Germany collected a huge amount of test data for Nikon F lenses, so we’ll check out some of the more important lenses over time now. The Sigma lens is a competitor to the Nikkor AF-S 105mm f/1.4E that we discussed some weeks ago. It has been discontinued for quite a while although you should be able to find it on the used market. It’s worth pointing out that the lens uses an electromagnetic diaphragm mechanism so only modern Nikon F-mount cameras are supported. Besides Nikon F, the lens was also made in Sony E, Sigma SA and L-mount.
Just by looking at the thing, you can conclude that it is built like a tank and just as heavy at 1.64kg. Consequently, Sigma also incorporated a dedicated tripod collar (Arca-Swiss compatible). It uses Sigma’s TSC (Thermally Stable Composite ) for the lens body. The huge focus ring turns smoothly. However, an aperture ring is not provided. The front filter size is 105mm, so filters aren’t exactly cheap if you need one. A deep, heavy-duty lens hood is part of the package.
The AF is very fast and near noiselessly on the Nikon D850 thanks to Sigma HSM (Hypersonic motor). Manual focusing is directly coupled rather than by-wire.
| Specifications | |
|---|---|
| Optical construction | 17 elements in 12 groups (3x FLD, 2x SLD, 1x aspherical) Fluorine coating (front element) |
| Number of aperture blades | 9 (rounded) |
| min. focus distance | 1m (max. magnification ratio 1:8.3) |
| Dimensions | 115.9 × 131.5mm |
| Weight | 1645g |
| Filter size | 105mm |
| Hood | barrel-shaped (bayonet mount, supplied) |
| Other features | dust- and splash resistant tripod-collar (Arca-Swiss compatible) |
| Mounts | Nikon F Sigma SA Sony E L-mount |
Distortion
Lenses of the DSLR era didn’t rely on autocorrection, so manufacturers went the extra mile and optimised this aspect. The Sigma 105mm f/1.4 DG HSM ART only produces a negligible amount of pincushion distortion (~0.2%).
Vignetting
You may suffer from the weight of these huge glass elements but on the positive side, the vignetting is lower than on the Nikkor AF-S 105mm f/1.4 E. At maximum aperture, the vignetting is still very visible at more than 2 EV (f-stops). Stopped down to f/2, this is reduced to 1 EV and beyond it’s not an issue anymore.
MTF (resolution)
The Sigma 105mm f/1.4 DG HSM ART produced great results in the lab here although it doesn’t reach the fantastic quality of the Nikkor AF-S 105mm f/1.4 E. The broader center quality is already excellent at f/1.4 and the outer image field reaches very good quality. Stopping down to f/2 primarily boosts the center. Outstanding quality across the frame is available at f/4. As usual, diffraction effects limit the quality from f/5.6, although it’s only more obvious from f/11 onward.
Please note that the MTF results are not directly comparable across the different systems! Below is a simplified summary of the formal findings. The chart shows line widths per picture height (LW/PH) which can be taken as a measure of sharpness. If you would like to know more about the MTF50 figures, you may check out the corresponding Imatest Explanations.
Chromatic Aberrations (CAs)
Chromatic aberrations (color shadows at harsh contrast transitions) are quite well controlled. At f/1.4, they stay just below 1px on average at the image borders. The CAs decrease a bit to medium aperture settings and increase very slightly again from f/8.
Bokeh
A 105mm f/1.4 lens is meant for shallow depth-of-field photography, so let’s check the bokeh aspects here.
Out-of-focus highlights (center) have a fairly clean inner substructure with only hints of “onion-rings”. There’s no outlining here whatsoever. The circular shape remains intact at f/2. The slightly more edgy aperture shape starts to show up from f/2.8.
The circular disc shape is only maintained near the image center. The deterioration to “cat eyes” starts at the midfield, and they are very obvious in the corners. Stopping down to f/2 restores most of the discs, and the corner discs are back to their circular shape at f/2.8.
The general out-of-focus rendition is very smooth in the image background (shown to the left below), but more nervous with double edges in the foreground (to the right below, sorry – there’s a bit of a reflection going on there).
Bokeh Fringing / LoCA
Bokeh fringing (non-coinciding focal planes of the various colors) is a common issue with relatively fast glass. As you can notice below, the halos have different colors – magenta (red + blue) in front of the focus point and green beyond. Unlike lateral CAs, bokeh fringing cannot easily be fixed in post processing.
The Sigma lens has its share of fringing as you can see below. The LoCAs are obvious at f/1.4 but much reduced at f/2. Traces remain at f/2.8 and the issue is mostly resolved from f/4.
In addition, these shots also illustrate the focus shift towards the rear when stopping down. The effect is emphasized in these images, which were shot near the lens’ minimum focus distance. At more field-relevant distances, the issue won’t really be noticeable.
Sample Shots
The Sigma 105mm f/1.4 DG HSM ART is quite a beast. Optically, it's great - very sharp fully open and truly superb at medium aperture settings. Lateral CAs are low and distortions are absent. Some vignetting is obvious at f/1.4, but much reduced at f/2 already. The bokeh is silky smooth in the image background. Less obvious "cat eyes" would have been nice given that the front element is so huge. Axial CA can show up in difficult scenes.
The build quality is superb. However, the size and weight will make you suffer - which is typical for many Sigma lenses of this era. Despite the big glass elements, the AF is quick on the D850.
In Nikon mount, the Sigma 105mm f/1.4 DG HSM ART faces stiff competition from the Nikkor AF-S 105mm f/1.4 E. The Nikkor is marginally better optically, but much more compact and lightweight. However, you should be able to find a good deal on the used market and the Sigma is also available in mirrorless mounts (Sony E, L-mount).
If you'd like to support our work, please consider shopping for this or other lenses via one of the following partners:
* KEH (used gear, US)
The Good
- Great image quality
- Superb build quality
- Nice bokeh (mostly)
The Bad
- Some axial CAs
- Very big and heavy
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Optical Quality
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Build Quality